Technical Field
The present invention generally relates to a flexible system for creating patterns of pillow bags. For example, the system relates to an apparatus and method for creating pillow bag patterns of various counts, product types, products sizes, product arrangements, and product orientations. In some embodiments, the apparatus and method for creating pillow bag patterns packs these patterns into various containers, for example, caddies, cases, trades, sacks, universal surfaces.
Additionally, the present invention generally relates to measuring a thickness of a moving pillow bag and using the measurement to pick and place the pillow bag. For example, the invention relates to an apparatus and method for measuring a thickness of a moving pillow bag and using the measurement to pick and place the pillow bag.
The present invention also generally relates to determining the position and orientation of a pillow bag and using the position and orientation of the pillow bag to pick and place the pillow bag.
In some embodiments, the pillow bag is easily damaged or difficult to accurately and precisely pick and place. In one embodiment a system for moving the pillow bag comprises a conveyor belt and a robot that is positioned to pick the bag from the conveyor belt and place the pillow bag in an array. For example, in one embodiment the position, orientation and measured thickness of the pillow bag is used to position the robot so that damage to the pillow bag and other pillow bags is avoided while a robot picks and places the pillow bag to form a desired pattern.
In some embodiments, the invention generally relates to a compound angled universal surface for receiving placed pillow bags and maintaining the pillow bags in a desired position and orientation while a pattern is formed, while the pillow bags are transported, while the pillow bags are transferred to an ultimate package or some combination thereof. For example, in one embodiment the surface is universal in the sense that the walls of the universal surface do not need to be adjusted to support pillow bags in a desired position and orientation (e.g. an upright position). For example, a top surface of the universal surface, upon which a pattern is placed, is at a compound angle so that one corner is lower than all the other corners. One result of the compound angle is that gravity tends to pull bags towards the lowest corner. Accordingly, in some embodiments the walls of the universal surface do not need to be adjusted to support pillow bags in upright position. Although some embodiments of the universal surface comprise a compound angle and a lowest corner, in other embodiments, the universal surface comprises a single angle and a lowest edge. For example, in embodiments with a lowest edge gravity tends to pull bags toward the lowest edge. Accordingly, the pillow bags tend to be held in place by gravity without, for example, needing to be constrained on all sides by walls.
The present invention also generally relates to a method and apparatus for a universal surface that is decoupled from a conveyor for the universal surface. For example, in some embodiments this decoupling allows the universal surface to travel along various paths to the pattern creation cells where the universal surface is filled with pillow bags by a robot or travel various paths to pattern transfer stations where completed patterns can be transferred to packaging.
The present invention also generally relates to an apparatus and method for transferring products from a universal surface to an ultimate package (e.g., box, case, sack, tray, carton, etc.). In one embodiment, a robot with an end effector transfers product from the universal surface to the ultimate package and the end effector comprises a vacuum nozzle and a finger wall which, for example, along with other crowder walls, can act like a shoehorn. In some embodiments, the universal surface comprises a mating or matching finger wall. In some embodiments, the end effector finger wall passes through the corresponding finger wall of the universal surface when the end effector picks product for placement in an ultimate package (e.g., cardboard box). In some embodiments, product is transferred to the universal surface from an alternate package by tipping the universal surface upside down.
The present invention also generally relates to an apparatus or method for a quality control system for conveying pillow bags, picking pillow bags, placing pillow bags, transferring pillow bags, or some combination thereof. In one embodiment, a pillow bag is rejected if it fails to meet at least one condition. In one embodiment, an input device can be stopped if any robot has been unable to complete its task of picking and placing the pillow bag before the pillow bag or a universal surface is conveyed outside the robot's area of influence.
Background
In many manufacturing, handling and transportation processes, pillow bags (e.g. bags of potato chips or cookies) need to be placed in specific patterns for placement in a sack, tray, box, wrap or other packaging. In many cases, the pillow bags have variable positions, orientations, or dimensions, such as thickness. For example, the position of a pillow bag on a conveyor belt constantly changes as the conveyor belt moves. In addition, the position of the pillow with respect to the conveyor belt can change. For example, the pillow bag may be closer to one edge of a conveyor belt than another. Another potential variable is the orientation of the pillow bag on the conveyor belt. The pillow bag can be tilted in one direction or another, be facing up, be facing down, or be rotated. Furthermore, the pillow bag can have variable bag dimensions in at least four situations. First, given a batch of bags from a single product manufacturing run, there are often variations in the size of the product. Second, bags in batches of a product run on different days can vary in size. Third, bag dimensions can vary for bags of different kinds of product or bags of product intentionally made in different sizes. Fourth, it might be desirable for bags with intentionally different sizes to be packaged together.
If pillow bags are placed as close to each other as possible to conserve space and reduce costs for packaging or storage, the placement of one pillow bag often depends on the placement of previous pillow bags. For example, after a first pillow bag is placed face-down in a package next to a wall, the second pillow bag can only be accurately placed next to the first pillow bag if the position of the first pillow bag is known. If the width and/or length of the first pillow bag are known, it can be used to place the second pillow bag as close as possible to a wall of the package while still leaving room for the first pillow bag. Such an arrangement can be desirable to save space.
In other applications, it can be desirable to form a particular pattern with pillow bags with varying positions, orientations, and dimensions. For example, these patterns can form an attractive or useful arrangement for displaying the pillow bags to consumers. However, the process of determining the position, orientation, and dimensions of pillow bags and then accurately and precisely placing them in a high quality pattern can be challenging. For example, the pillow bags are often filled with air and can change shape or incur damage upon contact with a measuring device or a pick and place robot. Furthermore, the pillow bags are often moving on a conveyor belt and this can further complicate the task of measuring, picking and placing the bags. Nonetheless, being able to determine the position, orientation, and dimensions of a moving, non-rigid pillow bag can be critical for some applications.
To understand why determining the position, orientation, and thickness of a pillow bag is important, it is useful to review a traditional process for putting pillow bags in a box as described with reference to FIG. 2A. In a first step 200, a batch of bags is produced with an assumed thickness. Second, in a picking step 202, a robot picks a bag using the assumed thickness from step 200. Third, in a placing step 204, after the robot picks the bag, it places the bag flat in a box. In placing the bag, the robot again uses the assumed thickness. For example, the assumed thickness is used to estimate how far the robot needs to stay from the box while placing the bag. If the robot gets to close to the box, the bag can be popped between the robot and the box. Fourth, in a repeating step 206, the steps of picking 202 and placing 204 are repeated until the box is full of bags.
As shown in FIG. 2A, traditional manufacturing, handling, and transportation processes have used assumptions regarding a pillow bag's thickness to pick and place the bag in a box. Thus, while the thickness of potato chip bags can vary due to the amount of air in the bags, in a traditional manufacturing and handling process, all the bags are assumed to have the same thickness for the purposes of placing the bags in a pattern. Accordingly, a pick and place robot is positioned based on the assumption that each bag has a given thickness. If the thickness of a particular bag varies significantly from the assumed thickness, it can result in damaged product or poor pattern creation. For example, if a bag is thicker than expected, the robot can get too close and pop the bag. Alternatively, if a bag is thinner than expected, the robot can remain too far away and miss the bag altogether. In some cases, when a bag has dimensions that vary from assumed dimensions, a robot can pick the bag insecurely. Then, as the robot moves with the bag, forces acting on the bag cause the robot to lose its hold or suction on the bag and hence drop the bag.
Ultimately, imprecision and inaccuracy related to pillow bag position, orientation, or thickness can result in misplaced and damaged bags, and introduce inefficiencies into the bag manufacturing, handling and transportation process. For example, because assumptions are used and actual product thicknesses can vary, tolerance must be built into a manufacturing, handling, and transportation system. This tolerance can take the form of leaving extra space on a conveyor belt or between bags in a package. However, this extra space can be wasted on the majority of bags which do not actually require extra space. Likewise, packages and equipment must be larger, resulting, for example, in greater expense, greater use of energy, and greater use of natural resources.
Down time to address dropped, damaged, or misplaced pillow bags is another inefficiency that can occur in a product manufacturing, handling and transportation process as a result of assumptions or inaccurate information regarding the dimensions of a product.
Another problem with existing pattern creation systems is their inability to efficiently and effectively form patterns, especially more complicated patterns.
What is needed is a new and innovative system capable of forming more complicated patterns in an effective and efficient way while limiting the amount of bags lost due to damage as a result of incorrect assumptions regarding bag dimensions.
Additionally, there has been no reliable method of determining the position, orientation, and dimensions of a moving pillow bag and using that information to pick and place the pillow bag to form a high quality pattern, while simultaneously avoiding damage to the pillow bag. Some traditional methods for picking and placing a pillow bag make assumptions as to the pillow bag's dimensions, but result in damage to the product or poor pattern creation or have a negative impact on production rate if the actual dimensions vary significantly from assumptions. Accordingly, a system capable of measuring the dimensions of a moving, non-rigid pillow bag is desirable for the additional accuracy, precision, reliability, efficiency and cost-effectiveness it can provide. Such a system is also desirable because it could increase quality by reducing waste. For example, the system could avoid loss or damage to bags that can occur when a robot picks from an inaccurate height.
What is needed is a new and innovative system capable of determining the position, orientation, and dimensions of a moving pillow bag and using that information to pick and place the pillow bag to form a high quality pattern, while simultaneously avoiding damage to the pillow bag. For example, a need exists for a system that measures the thickness of a pillow bag on a running conveyor and feeds this thickness measurement to a pick and place system. Additionally a need exists for the pick and place system to make a dynamic pick and dynamic place using the measurement to adjust both the pick and place locations for the pillow bag. Accordingly, poor quality patterns, inefficiency, damaged product, dropped product, and wasted product can be avoided while the accuracy, precision, reliability, efficiency, and cost-effectiveness of the pick and place system is simultaneously increased. In some embodiments, resources can be conserved and the environmental friendliness of the process can be increased.
Another problem that exists with conventional processes for picking and placing pillow bags is that if, for example, pillow bags were placed in a pattern on a tray, they would tend to move around. It would be advantageous to have an apparatus and method for maintaining the position and orientation of pillow bags once they have been placed in a pattern. It would also be advantageous if the apparatus (e.g., a tray) and method did not require adjustment for different shapes or sizes of pillow bag patterns. For example, it would be beneficial if the walls of the apparatus did not need to be positioned next to the pillow bags to maintain the pillow bags in a particular position or in an up-right orientation. It would also be advantageous if the apparatus and method could prevent the pillow bags from sliding or falling over. It would be further advantageous if the apparatus and method provided for uncoupling the apparatus (e.g. tray) from a conveyor so that the apparatus had freedom to travel along various paths, rather than a single path determined by a single conveyor.
Problems would also exist with respect to conventional methods for transferring objects if they were applied to pillow bags, for example, to transfer a pillow bag from a tray to final package. In some cases, transferring patterns would be slow or inefficient, for example, if the patterns were transferred manually or because a robot performing the motions required for a transfer can only move so quickly. In other cases, transferring patterns could result in disruption to the pattern or damage to pillow bags. It would be beneficial to have an apparatus and method for more efficiently and effectively transferring a pillow bag pattern from one surface to another surface, for example, from a tray to a package. It would also be desirable if the method and apparatus used components that reduced the amount of motion required to perform a pattern transfer and thereby increased the speed and efficiency of the transfer. For example, it would be advantageous, if the method and apparatus used components that were slotted so that the components could pass through each other when a pattern was transferred instead of having to move around each other. It would also be advantageous if the method and apparatus were compatible with transferring a pillow bag pattern from a surface with a compound angle. For example, for a process in which a pattern of pillow bags are pushed from a first surface to a second surface, if the first surface is slanted, but the second surface is flat, transferring pillow bags from the first surface to the second surface can be complicated and result in unacceptable disruptions to the pattern as it is transferred. It would also be advantageous if the method and apparatus were compatible with transferring a pillow bag pattern from a surface with a high coefficient of friction, which, for example, can help to keep the pillow bags from sliding. It would also be advantageous if such a method and apparatus could transfer the pattern using suction to lift the pillow bags off the high-friction surface rather than trying to push or slide the pillow bags off the surface. It would also be advantageous to be able to transfer pillow bags from the surface by flipping the surface over and using gravity, centripetal force, supports, or some combination thereof to prevent a pillow bag pattern from being disturbed to an unacceptable degree.
Another problem that exists for picking and placing pillow bags is that pillow bags that don't meet desired quality criteria can be included in a pattern or a pattern itself may not meet certain quality criteria. For example, a bag may have a smudged or off-center label, or a pattern may be incomplete because the tray bearing the pattern moved past a robot before the robot had time to place its pillow bag on the tray. As another example, some quality control systems that use weight to verify whether a specified quantity of pillow bags is present in a pattern do not work well when the pattern can comprise various types of products with various weights. Accordingly, it would be advantageous to have an apparatus and method for verifying the quality of pillow bags and patterns, including, for example, patterns that comprise products of variable number and type. It would also be desirable if such a method and apparatus could reject pillow bags if they fail to meet quality control criteria. It would also be advantageous if such a method and apparatus could provide for stopping a conveyor if a robot has not been able to pick and place or transfer a pillow bag.
It would also be beneficial if a system capable of determining the position, orientation and dimensions of a moving pillow bag could transmit information about the position, orientation and dimensions of the pillow bag to other systems. For example, it would be useful if one pattern creation cell with information about the position and dimensions of pillow bags could transmit this information to other pattern creation cells. As a result, a pattern created by one pattern creation cell could be added to or modified by another pattern creation cell. For example, one pattern creation cell could place bags in a first row on a tray, while a second pattern creation cell could place bags in a second row that is adjacent to the first row. Pattern creation cells could also be used together to create more complicated patterns. This would provide flexibility with respect to designing patterns and the efficiency and cost-savings with respect to reducing or eliminating misplaced and damaged product.
It would also be beneficial if a method and apparatus for picking and placing pillow bags were able to send information to a downstream device, for example a pattern transfer device. It would also be advantageous if the pattern transfer device could be used to transfer a pattern of pillow bags from one surface to another, and the pattern could comprise at least one column of bags. In transferring such a pattern, it would also be desirable if information on the length of the at least one column of bags could be used to improve pattern transfer performance.